Telegraph system.



G. E. HINES.

I TELEGRAPH SYSTEM. APPLIOATIOH rum) 11.13, 1907.

Patented Hem-.29, 1910.

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977,008. 7 Patented Nov. 29, 1910.

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' citizen of the United States,

GEORGE E. HINES, OF NEW YORK,

N. Y., ASSIGNOR OF ONE-HALF TO WILLIAM T.

DALEY, 0F BROOKLYN, NEW YORK.

TELEGRAPH SYSTEM.

Application filed. April 13,

To all whom it may concern:

Be it known that I, GEORGE E. HINEs, a residing at the city, county, and State of New York, have invented certain new and useful Improvements in Telegraph Systems, of which the following is a full, clear, and exact description. v

My invention relates to telegraph systems, and has for its object to transmit over a transmission line to distantstations along the line conductor dynamic currents of definite direction induced by a local or primary current.

Heretofore it has been proposed to impress electromotive forces on a telegraph line by means of induction coils having primary and secondary windings. No practical results, however, have ever been attained, for the reason that the secondary electromotive forces induced upon the make and break of the primary circuit have been impressed during such short periods as to be static intheir character, and have thus, instead of producing dynamic currents in the-transmission line, produced merely static eii'ects having no definite polarity, which are dissipated in other ways than through dynamic currents; I have discovered that, by the use of a combination of suitable apparatus, currents may be setup in the transmission line such as will inagnetize with a definite polarity telegraph apparatus at stations along, and in series with a line conductor. Moreover, the

currents impressed upon the transmission line in my system approach the sine Wave forni, the elements of this Wave being made up of a continuous growth of potential energy through an H1')]T[Clfll)l() period of time, and therefore are more easily transmitted and cause less interference with neighboring transmission lines than where an electromotive force from a constant potential source is impresseddirectly upon the line, as is the practice at the present time. In order to produce these dynamic effects, as distiu guishcd from the static cli'ects, of the apparatus heretofore proposed, I make the pr1- mary circuit of the induction apparatus one having a high time constant. The result of this is that when the primary circuit is made, the primary current gradually rises, the magnetism of the induction apparatus grad- ,ually rises, and the period of induction u on the secondary is correspondingly exten ed,-

' Specification of Letters Patent,

Patented Nov. 29, 1910. 1907. Serial no. asaoi mined by the time constant. The magnetism in the core rises at a rate determined by the primary current and the iron losses in the core. I preferably laminate the core so as to eliminate all eddy current losses. A secondary electromotive force is induced in the secondary winding during the Whole period of rise of the magnetism of the core, resulting in a secondary current flowing along the" line and during this period. Telegraph lines ordinarily have considerable capacity,-

which varies under varying conditions. I

therefore preferably introduce an adjustable self-induction coil in series with the secondary winding, so as to more or less neutralize this capacity. In order to make the fall of the primary current gradual upon the break of the primary circuit'at the transmission key, I shunt the transmission key by-a condenser. This permits the current Within the primary to fall gradually, and incidentally also protectsthe key from destructive arcing. The. decreaseof magnetism in the'core is determined by the decrease of current in the primary and also by hysteresis of the closed magnetic circuit core, and therehy extends overa considerable period, resulting in an induced secondary current flowing in a definite direction throughout the transmission line throughout that period.

I preferably make the induction coil in series with the secondary of such dimensions, as to more than neutralize the capacity of the line, sothat the time constant of the secondary circuit assists in causing the incircuitis closed through a teleduced current on the make as well as on the break to assume more nearly the sine wave form. v I

I place in series With the line at the transmitting stations, as well as at the receiving stations, relays which control local circuits for operating soundersand other indicating apparatus, the transmitting and relay mechanism being duplicated. at each station along the line. The telegraph or transmitting key is preferably such that the electro1not1ve forces impressed upon'the primary are all in the same direction, since areversal of the a electromotive force upon a single operatlon of the transmitting key is liable to send two impulses in the same direction and of substantially equal strength, instead of one 1mpulse in a given direction of double strength.

The following is a description of an embodiment of my invention, reference be ng had to the accompanying drawlngs, In which Figure 1 is a diagram of a system embodying my invention, and Figs; 2 and 3 are sectional plan and side elevations of the relay used therein.

Referring more particularly to the drawings, A A A represent batteries or other sources of constant potential.

B B B represent transformers, each having a laminated closed'magnetlc c1r cu1t,-t he primary B B B of which arean series with said sources. p

D D I) represent telegra h or transmltting keys in series with sai prlmaries and said sources.

E E E are condensers in shunt to the transmitting keys. I

F F F are polarized relays of suitable form, which are in series with the transmission line, and G G G are local circuits containing the sounders G or other receiving apparatus controlled by said polarized relay. The transmission line L 1s 1n series with the secondary B B B of the transformers, and also with the self induction coils H H. The transmission line at each end is grounded, as at I I. The two ter-' minal stations are the same. The intermediate stations of any desired number are as shown in the center. The line is ordinarily not grounded at this point but means for grounding it on either side of the transformer if desired are provided at P.

The relays are provided with jockey Wheels to keep the armatures in the positions in which they are thrown by currents from the sources A, it having been found that otherwise stray 'or earth currents of sufiicient strength to move them may pass over the line. The armatures are unretracted inasmuch as they remain in the posiation to which they are pulled by the electromagnets of the relays.

I The relays are more fully shown in 2 and 3., 'In these figures K is a polarized armature carried bya pivoted lever K. M M are two magnets wound so as to present poles of opposite polarity to the armature. M M are magnets in series with M M and Wound so that the pole of M is of opposite polarity to that of M of opposite polarity to that of M J is and the pole of M is the jockey wheel bearing against the tip of the lever K and held in position by a spring J attached to a pivoted block which is adjusted by set screws y" y" so as to be in proper position to engage the lever K but not to hold it too firmly.

In the operation of the system, when any primary circuit is closed through. its telegraph key, the primary current by reason of the time constant of the primary circuit, rises slowly, and the magnetism in the closed core of the transformer rises through a considerable period determined by the rise of the primary current and the hysteresis of the core. A secondary current is induced in the secondary coil which is transmitted along the line, having a duration corresponding to the riseof the magnetism of the closed core, and magnetizes the relays by a current of given direction. The polar zed armatures of the relays are by this current caused to move so' as to'complete the local circuits containing the receiving apparatus. When the primary current is broken by another movement of the telegraph key, another current flowing in the op osite direction to that before produced is in uced in the secondary circuit and flows along the transmission line. Thiscurrent continues during a period determined by the. gradual fall of the mag netism in the transformer core, and is of such duration as to cause the armatures and the polarized relays to move in the other direction and to open the local circuits con= trolled by the relays. The relays are preferably such as described, havin polarized armatures which are moved in 0th directions by the dynamic currents. The presence of the relays in series with the line introduces some self-induction therein and assists in overcoming the capacity of theline, and also reduces the tendency of the line circuit to reduce the time constant of the primary circuit. WVhere cables or a few stations only are employed I preferably use high potential primary circuits and step down transformers as shown, since I am thereby able to more easily obtain a higher time constant in the primaries;

As before stated, thecurrents up n the transmission line not only persist during a considerable period and-flow in a definite direction, but approximate at least the sine wave form, so as to be more/readily transmitted and not interfere seriously with the Working of other transmission linesby reason of their static induction, and this gradual rise and fall and duration are principally due to the high time constant in the primary, at the make, the capacity in the primary on the break. The self induction of the line circuit andthe hysteresis of the closed iron core also assist in attaining this necessary efl'ect.

What I claim is,---

l. The combination ofa mainline con l ductor continually grounded at each end'so as to provide a closed electric circuit, closed and a key-controlled primary circuit in selies with a source of constant current, relays having movable polarized armatnres and also in serieswith said conductor, and jockeys restraining said armatures against movement due to the action of stray currents.

.2. The combination of a main line conductor grounded at each end, closed magnetic circuit transformers having secondary windings in series with said conductor and a keyl i g controlled primary circuit in series with a source of constant current, relays having 5 movable polariyed. armatures also in SQIlCS With said conductor, jockeys restraining said armatures against movement due to the action of stray currents, and an adjustable self induction device also in series with said 20 conductor. 7,

GEORGE E. HINES.

lVitnesses IDA M. HUNZIKER, H. B. BROWNELL. 

